Biodiversity in the United States

Summary

NatureServe's Map of Biodiversity Importance (MoBI) is actually 4 main maps and 53 supporting maps.

The four maps showcase different aspects of biodiversity in the United States using Geographic Information System (GIS) technology. The maps are all based on data from NatureServe, which aims to assess the status and distribution of biodiversity across the United States. Each map uses a different metric to measure biodiversity and provides valuable insights into different facets of the complex and multifaceted concept of biodiversity. These maps can be used to inform conservation efforts and guide land use decisions to protect and preserve biodiversity in different regions of the United States. However, it is important to note that each map provides a limited view of biodiversity, and a comprehensive understanding of biodiversity requires consideration of multiple factors and metrics.

For example, it is difficult to determine which map shows the highest biodiversity in Arizona because each map uses a different definition of biodiversity. Map #1 shows the richness of imperiled species in the United States, but does not provide a total biodiversity count. The highest value in Arizona for this map is 11. Map #2 shows the summed range-size rarity of imperiled species in the United States, which measures the presence of imperiled species with small ranges, but does not necessarily capture total biodiversity. Maps #3 and #4 focus on areas of under-protected biodiversity importance of imperiled species and may not be as useful in determining total biodiversity.  It would be helpful to have a map that shows the total biodiversity of an ecoregion, which is not captured by any of these maps.

More resources

MoBI NatureServe Webpage

 Story map 

YouTube The Map of Biodiversity Importance | Dr. Healy Hamilton's Presentation at 2020 Esri UC

Detailed notes on each map

Map #1: Richness of Imperiled Species in the United States

1) Richness of Imperiled Species in the United States: link

a. High values identify areas where more imperiled species are most likely to occur.

b. Richness values are simply a tally of the number of species with habitat overlapping a cell.

c. Values range from 0 to 31, but the color ramp maxes out at 11.  

a. Highest value in AZ is 11.

b. Tenneessee has highest value upstream of Chattanooga and Knoxville along the Clinch river in the Cumberland river valley.

d. This is the prettiest map and easiest to interpret.

e. Most of the Sonoran desert has 0 imperiled species?  What about Pygmy owls?Sandhills east of Carlsbad only have 1 imperiled species (lesser prairie chicken).  What about lizards?  What about rare plants?

Map #2: Summed Range-size Rarity of Imperiled Species in the United States

2) Summed Range-size Rarity of Imperiled Species in the United States:  link

a. High values identify areas where species with very small ranges (and thus fewer places where they can be conserved) are likely to occur; the presence of multiple imperiled species contributes to higher scores.

b. Range-size rarity for each species is the inverse of the total area mapped as habitat. Summed range-size rarity is the sum of the range-size rarity values for all species with habitat that overlaps a cell.

c. The range for RSR values in cells containing species habitat is 0.0000002784 to 1.44584. A single species can have a value as high as 1.020335, which means just one 990-m cell contains all habitat for that species.  The RSR score for a species with habitat in two 990-m cells is 0.510167. 

d. This map is probably most important for conservation, and because its harder to interpret maybe is easier to use…less questions!

 Map #3: Protection-weighted Range-size Rarity of Imperiled Species in the United States

3) Protection-weighted Range-size Rarity of Imperiled Species in the United States: Link

a. High values identify areas where more unprotected, restricted-range species are likely to occur.  

b. Weighted based on how much of range is in protected areas.

c.  Each species was assigned a PWRSR score equal to the product of range-size rarity and the percent of habitat that is unprotected. The PWRSR raster sums these scores for all species with habitat that overlaps a cell.

d. Note:  Data based on USGS "GAP" analysis.  "Protected areas" include Wilderness and National Monument (GAP 1 and 2), but not Federal lands open to extraction like National Forests and BLM (GAP 3). 

Map #4: Areas of Unprotected Biodiversity Importance of Imperiled Species in the United States 

4)  Areas of Unprotected Biodiversity Importance of Imperiled Species in the United States: Link

a. Values of “1” identify areas where under-protected and range-restricted species are most likely to occur, including areas where the presence of multiple imperiled species contributes to higher scores

b. This is the same as #3 above, but with a cutoff value to make the map black and white.

c. AUBIs (Areas of unprotected biodiversity importance)